Enhanced coherence from correlated states in WSe₂/MoS₂ moiré heterobilayer

Moiré superlattices in van der Waals materials have emerged as a promising platform for studying the correlated states in condensed matter physics. These correlated states have substantial effects on the emission coherence, an important parameter for quantum light applications. However, the effect of correlated states on the excitonic emission coherence is largely unexplored. Here, we show that the coherence of moiré interlayer exciton emission in tungsten diselenide (WSe₂)/molybdenum disulfide (MoS₂) heterobilayers is sensitive to the correlated insulating states in this material. We demonstrate that the emission linewidth of interlayer exciton shows a dip at a particular power range, which we attributed to the excitonic (bosonic) interaction. Moreover, such linewidth minima also appear in the doping dependence of the photoluminescence spectrum at the integer electronic filling factor, f_el = 1, demonstrating the effect of the electronic (fermionic) correlated insulating state on the interlayer exciton emission coherence. Our results demonstrate the richness of exciton-exciton and exciton-electron interactions in moiré semiconductors and pave the way for engineering emission coherence by controlling such interactions.